It is quite often necessary, in the treatment of shoulder injuries and operations, to keep the shoulder in a position that is spaced apart with respect to the median plane of the body, with elevation of the associated arm.
However, devices proposed for this purpose up to now have not been entirely satisfactory.
The disadvantages of plaster thoracobrachial casts are well known; they are fixed, heavy devices, and making them is a long and complicated process. Also, to avoid any breakage, a rod for supporting the mass of the plaster must be integrated with it.
It is no longer entirely satisfactory to replace the plaster, which is a heavy and relatively fragil material, with synthetic thermoformable materials that are lighter and stronger, especially because of the cost price of the fitting process, since the basic material is expensive; all the constituent parts of the device must be molded while hot, piece by piece, before being soldered, again piece by piece and with heat. Fitting of the cast is laborious, and adjusting it by cutting off excess material once the device is in place produces sharp edges. Finally, as in the case of plaster, the device can be used only once.
Metal thoracobrachial devices are also expensive and heavy, since all the parts are made to measure and are articulated, which necessitates many screws and bolts and requires major adjustment.
Finally, in certain cases, simple supports of foam rubber or expanded plastic held in place with a bandage are used; however, in this case there is not always enough support and above all, as with all the other devices described above, it is not easy to vary the angle of abduction and keep it in the desired position for the required duration of treatment.
It will be appreciated that there is a need for a lighter abduction device that is easily adjusted on the patient, even by the attending physician, to attain the exact solution sought to the problem presented by the particular injury, whether it be dislocation of the shoulder, fracture of the upper end of the humerus, or any other surgery or post-operative treatment of the shoulder.